Mistral Small vs o3
A complete head-to-head: pricing, context window, benchmarks, modality coverage, and openness, with a programmatic verdict synthesized from the underlying data.
Updated
Mistral Small specs · o3 specs- PriceMistral Small
Mistral Small is roughly 13.3× cheaper on output tokens ($0.60 vs $8.00 per 1M).
- Context windowo3
o3 accepts 200K tokens vs 128K, 1.6× the room for long documents and codebases.
- BenchmarksTie
No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores.
- Modalitieso3
o3 supports 2 modalities (text, vision) vs 1 for Mistral Small.
- OpennessMistral Small
Mistral Small ships open weights (Apache-2.0); o3 is API-only.
It's a genuine coin-flip between Mistral Small and o3: 2 category wins each, with the rest tied. Mistral Small is roughly 13.3× cheaper on output tokens ($0.60 vs $8.00 per 1M). o3 accepts 200K tokens vs 128K, 1.6× the room for long documents and codebases.
No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores. They differ in modality coverage, Mistral Small handles text while o3 handles text, vision, which can be the deciding factor before you even look at benchmarks. Mistral Small ships open weights (Apache-2.0); o3 is API-only.
o3 is the newer of the two, released 7 months after Mistral Small, which usually means a more recent knowledge cutoff and updated safety post-training. Mistral Small is usually picked for cheapest llm and fastest llm workloads, while o3 sees more deployments in reasoning and math. If pricing matters more than every last benchmark point, run the numbers in the calculator below before committing.
Side-by-side specs
| Spec | Mistral Small | o3 |
|---|---|---|
| Provider | Mistral | OpenAI |
| Released | Sep 2024 | Apr 2025 |
| Modalities | text | text, vision |
| Context window | 128K tokens | 200K tokens |
| Max output | , | , |
| Input · 1M | $0.20 / 1M tokens | $2.00 / 1M tokens |
| Output · 1M | $0.60 / 1M tokens | $8.00 / 1M tokens |
| Knowledge cutoff | , | 2024-06 |
| Open weights | Yes (Apache-2.0) | No |
| API available | Yes | Yes |
Pricing at scale
What you'd actually pay at typical workloads. Numbers come from each model's published per-million-token rates.
- Light usage, 100k in / 50k out per day$1.50 vs $18.00
- Heavy usage, 1M in / 500k out per day$15.00 vs $180
- RAG workload, 5M in / 200k out per day$33.60 vs $348
Light usage, 100k in / 50k out per day: $1.50 vs $18.00 per month, model A comes out ahead. Heavy usage, 1M in / 500k out per day: $15.00 vs $180 per month, model A comes out ahead. RAG workload, 5M in / 200k out per day: $33.60 vs $348 per month, model A comes out ahead.
Estimated spend for the listed models at your usage. Numbers are derived from each model's published per-million-token rates.
- Mistral Small$0.050
- o3$0.600
Benchmarks compared
Only sourced numbers. Where a benchmark is missing for one model we show the available value rather than fabricating the other.
- HumanEval,95.0
- GPQA,87.7
Mistral Small fits when…
- Apache-2.0 open-weight
- Fast and cheap
- Cost-sensitive workloads, 13.3× cheaper than o3 on output tokens.
- Self-hosting and on-prem requirements, open weights (Apache-2.0).
o3 fits when…
- Industry-leading reasoning depth at launch
- Strong on math, science, and abstract puzzles
- Tool-use during reasoning loops
- Long-context tasks, handles 200K tokens vs 128K for Mistral Small.
- Multimodal needs covering vision.
Consider Mistral Large 2
Mistral's flagship API model, strong on code and reasoning, EU-friendly hosting.
Frequently asked
Is Mistral Small or o3 cheaper?
Mistral Small is cheaper at $0.60 / 1M tokens per million output tokens, vs $8.00 / 1M tokens for o3.Which has the larger context window?
o3 accepts 200K tokens vs 128K for Mistral Small.Is Mistral Small or o3 better for coding?
Both Mistral Small and o3 are competitive on coding benchmarks. See each model's individual spec page for HumanEval and SWE-bench scores where published. For an opinionated pick, consult our Best LLM for Coding ranking.Are either of these models open source?
Mistral Small ships open weights (Apache-2.0). o3 is API-only.When were Mistral Small and o3 released?
Mistral Small was released by Mistral on 2024-09-18. o3 was released by OpenAI on 2025-04-16.
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